Re: It needs to be an unknown
As the actor is playing someone so unique, he can't be associated with other roles.
Mozzer's most distinguishable feature is his jawline. Only James Van Der Beek and possibly Matt Dillon have that feature from all the people who've been suggested, but they're not right, as they're too rough and ready. Jude Law's features are too soft, and although Moz was effeminate in The Smiths, he always looked like a pretty boy, not androgynous like Law. And the best candidate, Joaquin Pheonix, is now associated with Johnny Cash (not to mention the fact that his cheekbones are just a bit too sculpted).
There's a writer and performer from the British comedy The Catherine Tate Show, called Matthew Horne (he appears in the sketch with the cockney grandma as her grandson) and looks-wise, he would be perfect; unfortunately i can't find a photo of him on google, but trust me, jaw, eyebrows, accent, he looks and sounds like a young Moz. But at the same time, it's about getting the singing voice and the mannerisms, to be honest, there aren't many actors who could pull it off.